机务英语口语

TMA - Terminal Control Area. An area of controlled airspace at the

intersection of airways in the vicinity of control zones (CTRs) around major airports.

TO - take-off (sometimes TKOF).

TODA - take-off distance available. Also TODR, take-off distance required, and TORA, take-off run available.

track - actual flight path of an aircraft over the ground.

transponder - airborne receiver/transmitter portion of the SSR system which receives the interrogation signal from the ground and automatically replies according to mode and code selected. Modes A and B are used for identification, using a four-digit number allocated by air traffic control. Mode C gives automatic altitude readout from an encoding altimeter.

transition altitude (TA) - altitude in the vicinity of an aerodrome at or

below which the vertical position of an aircraft is controlled by reference to altitude, i.e. with the aerodrome QNH set on its altimeter. Above transition altitude QNE is set and flight levels used. Also transition level (TL) at which a descending aircraft changes from FL to QNH.

trend - Met forecast for the next two hours, added to some METARs.

TSO - Technical Standard Order. A standard established by the U.S. FAA for quality control in avionics, instruments and other airborne equipment. If it complies, equipment is said to be \ non-TSO\

TTAF/E - total time airframe/engine,

TTSN - total time since new

TVOR - terminal VOR. A low-powered VOR located at or near an airport and used as an approach aid.

TWR - Tower (aerodrome control tower).

TWY - taxiway.

Tx - transmitter.

tyro - Can be used as an r/t call prefix by inexperienced pilots in distress or urgency situations to ensure they are not passed instructions beyond their capabilities. U

UAS - University Air Squadron.

UDF - UHF direction finding.

UFN - until further notice.

UHF - ultra-high frequency. Radio frequencies in the 300-3,000 MHz band.

UHMRA - Upper Heyford Mandatory Radio Area.

UIR - Upper InＦＯＲＭation Region, covering the same geographic areas as a FIR, but extending vertically upwards from 24,500 feet, within which certain

additional operational rules apply. Also UIS, Upper InＦＯＲＭation Service.

Unicom - privately-operated advisory A/G radio service at uncontrolled airfields (USA). UNL - unlimited

u/s - unserviceable (i.e not working) when applied to an aircraft or its equipment.

u/s - unserviceable (i.e not working) when applied to an aircraft or its equipment.

UTC - Co-ordinated Universal Time, ＦＯＲＭerly Greenwich Mean Time (see also Zulu). V

V-speeds - designations for certain velocities relating to aircraft operation, thus:

V1 decision speed, up to which it should be possible to abort a take-off and stop safely within the remaining runway length. After reaching V1 the take-off must be continued.

Va design manoeuvring speed. The speed below which abrupt and extreme control movements are possible (though not advised) without exceeding the airframe\ limiting load factors.

Vfe maximum flap extension speed (top of white arc on ASI). Vle maximum landing gear extended speed

Vmca minimum control speed (air). The minimum speed at which control of a twin-engined aircraft can be maintained after failure of one engine.

Vmo maximum operating speed. Also Mmo, Mach limit maximum operating speed. Vne never-exceed speed, \ Vno normal operating speed. The maximum structural cruising speed allowable for normal operating conditions (top of green arc on ASI). Vr rotation speed, at which to raise the nose for take-off.

Vso stalling speed at MTWA, in landing configuration with flaps and landing gear down, at sea level, ISA conditions (bottom of white arc on ASI). Vx best angle of climb speed on all engines. Vxse best engine-out angle of climb speed. Vy best rate of climb speed on all engines.

Vyse best engine-out rate of climb speed, \